多孔介质中甲烷预混气火焰传播特性实验研究

本文对甲烷预混气在多孔介质中的火焰传播特性进行了实验研究,在开口竖直管中充填多孔介质,通过改变预混气氧含量使火焰在不同多孔介质中传播并测量火焰传播速度。预混气中氧含量最高达到29％。实验结果表明:多孔介质中甲烷可燃预混气火焰传播速度大于其层流火焰传播速度,可达到5倍以上(当量比的甲烷-空气预混气);多孔介质当量孔直径越大,或预混气层流火焰速度越高,则预混气火焰传播速度越高;多孔介质中可燃混气的火焰传播界限变小,当量孔直径大的多孔介质其界限值较大。实验结果与Babkin提出的多孔介质中的火焰传播机理相符。

EXPERIMENTAL INVESTIGATION OF FLAME PROPAGATION OF METHAN MIXTURE IN POROUS MEDIA

In this paper, the flame propagation of methan mixture in porous media were investigated. The vertical test tube was one end open and the flame propagated in various porous media by varying the oxygen content up to 29% in the mixture. Several practically relevant highly porous media like foams and fabric lamellar structures were tested. It was found that the flame propagation speed in porous media is much higher than the laminar flame speed and reaches 5 times higher for methan-air in porous media of great equivalent diameters when the air ratio equal 1. The greater the equivalent pore diameter, the higher the flame propagation speed, especially for the mixture of higher laminar flame speed. It was also shown that the methan mixture propagated in porous media in smaller air ratio limits, though the ranges were enlarged for porous media of great equivalent diameters. The results are in agreement with the flame propagation mechanism proposed by Babkin.